研究表明 miRNA 与肿瘤的发生、转移、耐药等病理进程密切相关。我们前期发现miR-551在胃癌组织和细胞中，其表达均明显下调，且与胃癌的临床病理分期关系密切。本项目在前期研究基础上，拟建立miR-551稳定过表达及沉默的胃癌细胞系，并构建裸鼠模型，通过生长曲线分析、集落形成、流式细胞分析及侵袭转移相关实验等，探讨miR-551参与胃癌发生发展的作用；通过生物信息学方法、蛋白芯片技术、双荧光素酶报告基因分析、染色质免疫共沉淀及凝胶滞留实验等技术，深入探讨miR-551调控下游靶基因及上游转录调控的机制，阐明miR-551参与胃癌发生发展的分子机制。通过我们的研究，将为胃癌发病机制以及未来的靶向治疗提供新的思路和理论基础。并有望提供新一代特异性高的理想分子标记物应用于胃癌的早期诊断及预后判效。

According to the papers published recently, microRNA is really important for the tumor formation, metastasis and drug resistance. Our preliminary data demonstrated that the expression of miR-551 were very low in gastric cancer tissues and related cell lines, also which is closely associated to the clinicopathological stages. Based on the above studying, we will construct the relevant stable gastric cancer cell lines. They are miR-551 co-overexpression stable cell lines and co-knockdown stable cell lines, respectively. Moreover, we are going to use the nude mice to construct the relevant animal models. We will clarify the function of miR-551 in gastric cancer after several related experiments: tumor growth curve analysis, colony formation assay, flow cytometry and invasion assay. Furthermore, we will clarify the mechanism that how the two genes regulate their downstream genes and how they effect their transcriptional ways in gastric cancer. Apparently, the Bioinformatics technology, protein microarray, Dual-Luciferase Reporter Assay, Chromatin Immunoprecipitation Assay and Gel shift technique are necessary for our research. Hopefully, some new and useful approaches can be revealed via this studying to cambat gastric cancer. We also try to find a more-specific ideal molecular marker which could be valuable and helpful for the early diagnosis and prognosis evaluation of gastric cancer.